Hypertrophic and keloid scars are abnormal scars that develop from the biological process of wound repair in the skin. Hypertrophic scars and keloids are raised, thickened, discolored scars that are typically stiffer than the surrounding skin. Both types of scars are often tender, itchy, and even painful.
Keloid scars are the result of an overly aggressive healing process. These scars extend beyond the original injury. Over time, a keloid scar may affect mobility. Left untreated, keloids can continue to grow quite large. Hypertrophic scars are raised and red scars that are similar to keloids, but do not breach the boundaries of the injury site.
Most people desire to minimize the appearance of such scars. Several treatments and preventative methods exist, including steroid injections and surgery.
Silicone is a noninvasive treatment that has demonstrated significant improvement in the overall look and texture of scars, including improvement in scar elasticity in those prone to abnormal scarring. Various prescription and over-the-counter products are available, including Applicant's own ScarAway™ silicone scar sheets. The differences among these products generally lie in their physical characteristics. For instance, sheets are provided with and without adhesive backing. Other products include polyurethane foam, pressure garments, splints, silicone gels, ointment sprays to form a thin coat of silicone over skin surface, and liquid strips enhanced with various vitamins or steroids.
Silicone gel sheeting, which is standard of care for plastic surgeons, has been widely used since the 1980s. There are several hypotheses that try to explain its efficacy in treating hypertrophic and keloid scars. Possible mechanisms include increased temperature, hydration caused by occlusion of the underlying skin, increased oxygen tension, direct action of the silicone oil, and polarization of the scar tissue caused by the negative static electric charge generated by movement of the silicone. See Berman et al., A Review of the Biological Effects, Clinical Efficacy and Safety of Silicone Elastomer Sheeting for Hypertrophic and Keloid Scar Treatment and Management, Dermatological Surgery 33:11 November 2007, pp. 1291-1303. A drawback of silicone sheeting is that it must be worn for 12 hours per day for 2 to 3 months to be effective.
Another known method of scar treatment is pressure therapy, which is particularly useful for hypertrophic burn scars. It is recommended that pressure be maintained between 24 and 30 mm Hg for 6 to 12 months for this therapy to be effective. More costly or invasive techniques include radiotherapy, laser therapy and cryotherapy.
Massage is a physical management option for scar treatment often used by physical therapists, occupational therapists and other allied health care professionals, but has not been clinically proven by long-term studies. Massage is often combined with other scar management techniques to treat burn scars.
U.S. Pat. No. 7,241,451 to Edell et al. discloses a topical cream containing silicone and sunscreen that is applied to scars. Silicone is only 1.0 to 7.0% of the composition. The cream is to be applied twice daily and massaged into the scar area for two to three minutes to aid in breaking up collagen or scar tissue, reducing the appearance of scar tissue. However, the massage method is not described and the amount of cream applied is not controlled.
Because of the pain, itching and unpleasing appearance associated with hypertrophic and keloid scars, there is a desire to have new and improved techniques to treat and prevent the formation of these scars. It also desirable for these techniques to be affordable, available for over-the-counter purchase, easy to use and involve minimal time commitment.